The reactivity of uranium compounds towards small molecules typically occurs through stoichiometric rather than catalytic processes. Examples of uranium catalysts reacting with water are particularly scarce, because stable uranyl groups form that preclude the recovery of the uranium compound. Recently, however, an arene-anchored, electron-rich uranium complex has been shown to facilitate the electrocatalytic formation of H₂ from H₂O. Here, we present the precise role of uranium–arene δ bonding in intermediates of the catalytic cycle, as well as details of the atypical two-electron oxidative addition of H₂O to the trivalent uranium catalyst. Both aspects were explored by synthesizing mid- and high-valent uranium–oxo intermediates and by performing comparative studies with a structurally related complex that cannot engage in δ bonding. The redox activity of the arene anchor and a covalent δ-bonding interaction with the uranium ion during H₂ formation were supported by density functional theory analysis. Detailed insight into this catalytic system may inspire the design of ligands for new uranium catalysts.

铀化合物对小分子的反应性通常通过化学计量而不是催化过程发生。与水反应的铀催化剂的例子特别稀少，因为形成了稳定的铀酰基团，阻止了铀化合物的回收。然而，近来，芳烃-锚定，富电子铀复杂已经显示出促进H的电催化形成₂选自H ₂ O.在此，我们提出的确切作用铀芳烃δ接合在催化循环的中间体，以及H ₂的非典型两电子氧化加成的详细信息O为三价铀催化剂。通过合成中价和高价铀-氧代中间体并通过与结构相关的复合物进行不能进行δ键的比较研究，探索了这两个方面。密度泛函理论分析支持了芳烃锚的氧化还原活性以及在H ₂形成过程中与铀离子的共价δ键相互作用。对这种催化系统的详细了解可能会激发新型铀催化剂配体的设计。